Required download missing

Haileymartini Said:

"Required download missing: Hi there, I recently inherited a Mac from the family and I am trying to erase the drive and redownload OS X El Capitan. When I restart the computer it takes me to the OS X utility screen. Upon trying to download a new version of OS, I am notified that a required download is missing. Does anyone know how to fix this??"

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Reinstalling the macOS:

Go Here: How to Reinstall macOS from macOS Recovery - Apple Support

Important: First, Back Up your Mac:

Create a Time Machine backup of your Mac, so that you can have something to restore your Mac from, should anything go wrong with the reinstall. Take this as a learning experience, knowing to always create a backup of your Mac, prior to making any major changes to it (i.e. update installation)

Reinstalling the macOS Anew:

See if this Site Helps: How to Reinstall the macOS Anew - No TMB Prior to Upgrade - User Tip. Format the hard drive with El Capitan, on step D.

In Depth:

Pretty much, it is a matter of:

1. Erasing: and formatting your hard drive to APFS
2. Installing: El Capitan via a USB Bootable Installer
3. Restoring: info from a Time Machine Backup, using Migration Assistan

Have you erased the mac yet? I hope not.

Do not rely on Apples Recovery Servers to reinstall older OS's.

If you haven't erased the drive boot back to your mac and follow the instructions to

download a copy of El Capitan, make the Install OS X El Capitan.app

and then create a bootable USB flash drive installer.

Click on the link below,

How to get old versions of macOS – Apple Support

Go to Download OS and click on OS X El Capitan 10.11

this downloads InstallMacOSX.dmg to your Downloads folder.

The next section can only be done on a mac that is capable of running El Capitan.

This includes macs that have the potential to run El Capitan but have been upgraded to a newer OS.

A mac that came preinstalled with an OS later than El Capitan will refuse to do the next bit.

When downloaded open to InstallMacOSX.pkg, double-click on

that and an installation window will open, this does not install El Capitan

but converts the InstallMacOSX.pkg to the Install OS X El Capitan.app which 

you will find in your Applications folder, it should be 6.2GBs in size.

(If the installation window asks which disk you want to install to, you must pick 

the disk that you are booted to at the time. Not any internal or external disk that 

you want to eventually install El Capitan on, that is for later.)

To start the installation of El Capitan double click on the Install OS X El Capitan.app.

The copy of the install app self deletes after installing El Capitan, so make sure you keep a copy of the 

InstallMacOSX.dmg if you need it in future, or you could just make a copy of the Install OS X El Capitan.app 

prior to installing and moving it to an external drive for safe keeping. 

It is also possible to create a bootable USB installer disk using the Install OS X El Capitan.app in the Applications 

folder and the createinstallmedia command in the Terminal app. 

Read the instructions here,

How to create a bootable installer for macOS – Apple Support

If you have erased read the following.

The certificates for several of Apples OS's expired in October 2019, Apple haven’t bothered getting these updated on 

their Recovery Servers with valid certificates. 

Try this workaround, we are going to set the time and date on your mac to a date previous to the expiry date of the certificates.

Connect your mac to your router via cable, not WiFi

Boot to your Recovery HD, click on Utilities in the menubar select Terminal.

Make sure WiFi is switched off, it can reset the date back to today.

Enter a new date, for example or just copy and paste

sudo date -u 011421002017

press Return

enter your password

press Return

If Terminal returns an error saying sudo : command not found, then try again without sudo.

just enter 

date -u 011421002017

press Return

You won't be prompted for a Password if you did not need to use sudo

Once the date has changed you can quit Terminal.

Now try downloading the OS.

Click on Install OS X, press Continue.

If this works then when the OS is installed and booted up you can Open System Preferences> Date & Time

and reset the time back to today.